That's a truly funny statement, that Christ's future "thousand years" reign is considered a figure or speculation by most of the Christian Church. That truly is wishful thinking on your part. Does your belief in such a fallacy as that help make you feel more secure by holding to such a fallacy?
The future "thousand years" reign by Lord Jesus AND His faithful elect, on earth, with His promised "rod of iron", over all nations, will be a literal physical reign upon this earth. Zechariah 14 specifically shows His literal, physical return back to this earth on the "day of the Lord", and bringing all the saints with Him.
Rev 5:9-10
9 And they sung a new song, saying, "Thou art worthy to take the book, and to open the seals thereof: for Thou wast slain, and hast redeemed us to God by Thy blood out of every kindred, and tongue, and people, and nation;
10 And hast made us unto our God kings and priests: and we shall reign on the earth.
KJV
Rev 20:4-6
4 And I saw thrones, and they sat upon them, and judgment was given unto them: and I saw the souls of them that were beheaded for the witness of Jesus, and for the word of God, and which had not worshipped the beast, neither his image, neither had received his mark upon their foreheads, or in their hands; and they lived and reigned with Christ a thousand years.
5 But the rest of the dead lived not again until the thousand years were finished. This is the first resurrection.
6 Blessed and holy is he that hath part in the first resurrection: on such the second death hath no power, but they shall be priests of God and of Christ, and shall reign with Him a thousand years.
KJV
Rev 22:3-5
3 And there shall be no more curse: but the throne of God and of the Lamb shall be in it; and His servants shall serve Him:
4 And they shall see His face; and His name shall be in their foreheads.
5 And there shall be no night there; and they need no candle, neither light of the sun; for the Lord God giveth them light: and they shall reign for ever and ever.
KJV
I'll bet you didn't even know that only those of The Just in Christ's future thousand years reign will be allowed to approach Him and serve Him at His table. You probably don't recall Jesus pointing to the marriage supper He promised to have with His servants in His future Kingdom...
Matt 26:29
29 But I say unto you, I will not drink henceforth of this fruit of the vine, until that day when I drink it new with you in My Father's kingdom.
KJV
You probably also missed the Revelation 22:14-15 Scripture that reveals the future Millennium reign by Jesus with the wicked dwelling outside the gates of the holy city, while His elect only are allowed inside with access to the Tree of Life, a real, literal tree bearing its many fruits per Ezekiel 47.
The Amillennial doctrine from men is designed to support Satan's plan for takeover of this earth, and setup his kingdom in the last days over the nations. It is strongly a doctrine held by supporters of a "one world government".